# provider-custom/mjs (Custom Provider Mjs) You can run this example with: ```bash npx promptfoo@latest init --example provider-custom/mjs cd provider-custom/mjs ``` ## Usage This example uses a custom API provider in `customProvider.mjs`. It also uses CSV test cases. Run: ```bash promptfoo eval ``` Full command-line equivalent: ```bash promptfoo eval --prompts prompts.txt --tests vars.csv --providers openai:chat --output output.json --providers customProvider.js ```